@article { ISI:000250410500033, title = {Synthesis and characterization of new aromatic polyesters containing biphenyl side groups}, journal = {Journal of Applied Polymer Science}, volume = {106}, number = {5}, year = {2007}, month = {DEC}, pages = {3105-3110}, publisher = {JOHN WILEY \& SONS INC}, type = {Article}, address = {111 RIVER ST, HOBOKEN, NJ 07030 USA}, abstract = {

Aromatic polyesters containing biphenyl side groups were synthesized by phase-transfer catalyzed interfacial polycondensation of 1-(4-biphenylyl)-1,1-bis(4-hydroxyphenyl) ethane (BBHPE) with terephthaloyl chloride (TPC), isophthaloyl chloride (IPC), and a mixture of TPC/IPC (50: 50 mol ratio). Copolyesters were synthesized by utilizing different molar proportions of BBHPE and 4,4-isopropylidenediphenol (BPA) with IPC and TPC. The inherent viscosities of polyesters were in the range 0.44-1.26 dL/g. All the polyesters were soluble in organic solvents such as dichloromethane, chloroform, tetrahydrofuran, meta-cresol, pyridine, N,N-dimethylformamide, N,N-dimethylacetamide, and 1-methyl-2-pyrrolidmone. Tough, transparent, and flexible films could be cast from chloroform solutions of these polyesters. WAXD measurements indicated that all the polyesters and copolyesters were amorphous in nature. Glass transition temperature of polyesters were in the range 198-256 degrees C, while the initial degradation temperature of polyesters were in the range 444-481 degrees C. Copolyesters derived from BBHPE exhibited improved solubility and higher glass transition temperatures compared to the corresponding polyesters based on BPA. (c) 2007 Wiley Periodicals, Inc.

}, keywords = {Aromatic polyesters, biphenyl side groups}, issn = {0021-8995}, doi = {10.1002/app.25862}, author = {Honkhambe, Pandurang N. and Avadhani, C. V. and Wadgaonkar, Prakash P. and Salunkhe, Manikrao M.} } @article { ISI:000263629200030, title = {Synthesis and characterization of new polyimides containing pendent pentadecyl chains}, journal = {European Polymer Journal}, volume = {45}, number = {2}, year = {2009}, month = {FEB}, pages = {582-589}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A new unsymmetrical aromatic diamine, viz., 4-pentadecylbenzene-1,3-diamine was synthesized through a series of reaction steps starting from 3-pentadecylphenol. 4-Pentadecylbenzene-1,3-diamine was employed to synthesize a series of new polyimides by one-step polycondensation in m-cresol with four commercially available aromatic dianhydrides. viz., 3,3{\textquoteright},4,4{\textquoteright}-biphenyltetracarboxylic dianhydride (BPDA), 3,3{\textquoteright},4,4{\textquoteright}-benzophenone-tetracarboxylic dianhydride (BTDA), 4,4{\textquoteright}-oxydiphthalic anhydride (ODPA) and 4,4{\textquoteright}-(hexafluoroisopropylidene)diphthalic anhydride (6-FDA). Inherent viscosities of resulting polyimides were in the range 0.33-0.67 dL/g and number average molecular weights were in the range 14,700-52,200 (GPC, polystyrene standard). Polyimides containing pendent pentadecyl chains were soluble in organic solvents such as chloroform, m-cresol, N,N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidinone (NMP), pyridine and nitrobenzene. Strong and flexible films of polyimides could be cast from their chloroform solutions. Polyimides exhibited glass transition temperature in the range 158-206 degrees C. The temperature at 10\% wt. loss (T(10)). determined by TGA in nitrogen atmosphere, of polyimides was in the range 470-480 degrees C indicating good thermal stability. (C) 2008 Elsevier Ltd. All rights reserved.

}, keywords = {Cashew nut shell liquid, Glass transition temperature, Pendant pentadecyl chain, polyimides}, issn = {0014-3057}, doi = {10.1016/j.eurpolymj.2008.11.013}, author = {Sadavarte, Nilakshi V. and Halhalli, Mahadeo R. and Avadhani, C. V. and Wadgaonkar, Prakash P.} } @article { ISI:000297269700002, title = {Synthesis and characterization of new organosoluble aromatic polyamides and polyazomethines containing pendent pentadecyl chains}, journal = {High Performance Polymers}, volume = {23}, number = {7}, year = {2011}, month = {NOV}, pages = {494-505}, publisher = {SAGE PUBLICATIONS LTD}, address = {1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND}, abstract = {

New aromatic polyamides and polyazomethines containing pendent pentadecyl chains were synthesized by polycondensation of pentadecylbenzene-1,3-diamine with (i) four commercially available aromatic diacids, viz., biphenyl-4,4{\textquoteright}dicarboxylic acid, 4,4{\textquoteright}-oxybisbenzoic acid, terephthalic acid and isophthalic acid, and (ii) dialdehydes, viz., terephthaldehyde, isophthaldehyde and a 50 : 50 mol\% mixture of terephthaldehyde, and isophthaldehyde, respectively. Inherent viscosities of polyamides and polyazomethines were in the range 0.35-0.56 dL g(-1) and 0.33-0.38 dL g(-1), respectively, indicating the formation of medium molecular weight polymers. The presence of pendent pentadecyl chains in polyamides and polyazomethines led to an improvement in their solubility in organic solvents. Polyamides could be cast into flexible, transparent and tough films from their solution in N,N-dimethylacetamide while polyazomethines could be solution cast into transparent, flexible and stretchable films from their CHCl(3) solution. (1)H-NMR studies based on amide proton signals and azomethine proton signals indicated the presence of constitutional isomerism in the polyamides and polyazomethines. Wide-angle X-ray diffraction patterns exhibited broad halo indicating that the polymers were amorphous in nature. X-ray diffractograms also displayed sharp reflections in the small angle region (2 theta approximate to 3 degrees) indicating the formation of layered structure arising from packing of flexible pentadecyl chains. The glass transition (T(g)) temperatures of polyamides were in the range 169-215 degrees C while T(g) values for polyazomethines were in the range 16-55 degrees C. The temperature for the 10\% weight loss of polyamides and polyazomethines were in the range 430-460 degrees C and 425-440 degrees C, respectively, in a nitrogen atmosphere, which indicated their good thermal stability. Polyazomethines were also characterized by UV-Vis and photoluminescence spectroscopy and optical band gap (E(g)) values, calculated according to the maximum of the UV absorption, were found to be in the range 2.82-3.10 eV.

}, keywords = {High performance polymers, optical band gap, polyamides, polyazomethines, solubility}, issn = {0954-0083}, doi = {10.1177/0954008311417316}, author = {Sadavarte, Nilakshi V. and Avadhani, C. V. and Wadgaonkar, Prakash P.} } @inbook {44022, title = {Step-growth polymers from cashew nut shell liquid (CNSL)-based aromatic difunctional monomers}, booktitle = {Cashew Nut Shell Liquid}, year = {2017}, pages = {163-214}, abstract = {

Cashew nut shell liquid (CNSL) is an attractive renewable resource material which is available in abundance (44,50,000 tonnes worldwide and 7,53,000 tonnes in India in 2013) at low cost (around 0.27 $/kg in 2015) and is mainly composed of anacardic acid, cardanol, cardol and 2-methyl cardol. Cardanol is obtained as a major product during hot oil extraction or roasting process of CNSL. Cardanol possesses interesting structural features. The aromatic ring of cardanol can undergo electrophilic substitution reactions; the unsaturated side chain can undergo epoxidation, hydrogenation, metathesis, etc., while the phenolic hydroxyl group can undergo various reactions such as esterification and alkylation. Such opportunities of chemical modifications offered by cardanol have been extensively explored to synthesise a range of interesting aromatic difunctional monomers that have subsequently been utilised to prepare a host of step-growth polymers. Summarised herein are research efforts that have contributed towards the synthesis of step-growth polymers based on aromatic difunctional monomers derived from cardanol. The properties of high-performance polymers, with a particular focus on processability and thermal characteristics, are highlighted.

}, doi = {10.1007/978-3-319-47455-7_9}, author = {Chatterjee, Deepshikha and Sadavarte, Nilakshi V. and Shingte, Rahul D. and More, Arvind S. and Tawade, Bhausaheb V. and Kulkarni, Arun D. and Ichake, Amol B. and Avadhani, C. V. and Wadgaonkar, Prakash P.} }